Air heating and conditioning apparatus



Oct. 3, 1939. c, H, WAGNER 2,174,710

AIR HEATING AND CONDITIONING APPARATUS Filed Jmly 2, 1957 INVENTOR C/zarksHWqgizer BY g .M

ATTORNEYS Patented Oct. 3, 1939 PATENT OFFICE AIR HEATING AND CONDITIONING APPARATUS Charles H. Wagner, Camden, J. Application July 2, 1937, Serial No. 151,627

13 Claims.

The ordinary fuel used in a household heater contains a large percentage of hydro-carbons, which when oxidized by combustion; will produce a large amount of water vapor. For example, in

L the average house burning 4'76 cu. ft. of 500 B. t. u. gas per hour, there will be produced about 85 gallons ofmoisture in 24 hours. Since it requires only about 6 to 7 gallons of water per 24 hours to maintain a relative humidity of 40% at 72 F. in

10 any ordinary house, it is seen that there is an ample supply of available moisture that can be used for properly humidifying said house.

One object of the present invention is to provide a process and apparatus for utilizing the water vapor naturally present in the gases of combustion of gases burned in a heating unit, for air conditioning a room.

The invention is applicable for use where the gaseous fuel being burned contains relatively so large percentage of free or combine hydrogen and producing a relatively large percentage of moisturein the combustion gases. It is not applicable where coal or oil is used as the fuel and where the percentage of moisture is low and there 5 is liability of odors or carbon monoxide gas resultingfrom incomplete combustion.

For carrying out this object, the temperature of the combustion gases is lowered below the dew point so as to condense a portion of the moisture.

30 A controlled amount of the gases saturated with moisture is then introduced into the room to be humidified.

Another object is to provide a process and apparatus for removing objectionable or dangerous 4 ingredients from the combustion gases before said gases are'injected into a room for air ,conditioning purposes.

This object is achieved by the washing and scrubbing action of the dropping particles of con- 40 densed water vapors in the gases of combustion.

Another object is to provide a process and apparatus, which utilizes the waste heat from the,

gases of combustion byheating a supply of air to be injected into a room, and which at the same 65 time lowers the temperature of said gases to bring the vapor contents nearer the dew point and,

thereby facilitating the use of the moisture for air humi'difying purposes.

Another object of the present inventionjis to provide a combined heating and air conditioning unit-of the type referred to, which is operated automatically in its entirety.

Various other objgcts, features and advantages of the present invetions will be apparent from the following particular description, and'from an inspection of theaccompanying drawing in which the single ,figure shows an apparatus, somewhat diagrammatic and partly in section embodying the present invention for the purpose of illustration, and adapted for carrying out the process of 5 the present invention.

In carrying out the process of the present invention, the temperature of the flue or combustion gases from a heater is lowered sufficiently to saturate said gases for room humidifying pu'r- 10 poses and at the same time to effect condensation of a good part of its water vapor content. The condensed water in dropping across the path of movement of the gases, washes and scrubs said gases of its objectionable ingredients including soot, and dust, and renders said gases suitable for air conditioning purposes. The lowering of the temperature of the flue gases is efiected by passing said gases in heat exchange relationship with fresh air, the resultant heated fresh air being injectedinto the room to supplement the direct heating from the heater unit. I

The apparatus shown in the accompanying drawing comprises an ordinary furnace l0, which may be of any suitable construction, but whichis advantageously of the steam or hot water type having an oil or gas burner. This furnace is shown mounted in the cellar of an ordinary home below the ground floor II, and has the conventional steam or hot water piping system l2 leading to a series of radiators l3 disposed respectively in rooms A.

The combustion gases from the furnace to are delivered from the upper end of said furnace, through a flue or pipe "Heading into the bottom of an insulated heat exchanger H, which includes a series of staggered horizontal tubes l8, advantageously provided with the usual radial'fins l9 for increasing their heat exchange surfaces. The tubes l8 are expanded at their ends into 40 header plates 20 spaced from the side walls 2| and 22 of said heat exchanger to form an inlet chamber 23 and an outlet chamber 24 on opposite ends of said series of tubes. The wall 22may be hinged to form'a clean-out door, and is fitted with a heavy glass pane whereby the condition of the chamber 24 may be inspected from the outside thereof. Connected to the bottom of this chamber 24 is a drain pipe 24a through which flows the condensed moisture with such impurities of the gas mixture as may be in solution or suspension, and which have been scrubbed from'the flue gases by the descending droplets of condensedmoisture.

Disposed below the tubes I8 is a removable and cleanable flltering bed 21, preferably made of mineral wool and open at its lower side to the atmosphere to permit admission of outside air through said bed and around the tubes I8. This air is barred from intermixture with the flue gases in the heat exchanger i! by the header plates 20, which isolate the two chambers 23 and 24 from said air.

Disposed at the upper end of the heat exchanger unit I1, is a cupola 25, provided at its upper end with branch ducts 26, which extend vertically through the floor and if desired through room walls 28, to the usual type of hot air registers.

In order to draw air into the heat exchanger unit through the filter bed 21, there is provided in the cupola 25 a pair of centrifugal fans 30, mounted on a common shaft 3|, driven by a suitable motor 32 disposed outside of said unit.

Connected to the bottom of the chamber 24 of the heat exchanger I1, is a conduit 35 leading to the inlet of an induced draft fan 36, which is driven from a suitable motor 31 and which has an outlet connected to a duct 38, branching at its upper end into a conduit 40 leading into a chimney 4|, and a conduit 42 leading into the heat exchanger above the series of tubes l8. The branch conduit 40 has a check valve 44 opening towards the chimney 4|, and the branch conduit 42 has a damper 45 automatically controlled from a motor or solenoid 46 controlled in a manner to be hereinafter described. I

As is common in many types of gas furnaces the flue pipe I6 may be provided with a series of cir- 36 cumferential slots 50 encircled by a bell 5| connected to said pipe. These slots 50 may be provided either on the outside of the furnace It or in the inside of the casing of the furnace, as shown in the drawing, and the portion of the furnace wall opposite these slots may-have an opening 52 covered with a grille 53. The draft induced by the blower may thus draw in air to dilute, cool and reduce the absolute humidity of the resulting air" and flue gas mixture.

The pipe l6 during normal operations is under a slightvacuum due to the induced or forced draft in the system, so that air is admitted through the slots 50 and into the pipe l6, and is carried with the flue gases into the heat exchanger The temperature in the rooms is controlled by a thermostat 60 in one of said rooms, and the humidity is controlled-by a hygrostat 6|, these control members being connected'by conductors 62 to a relay unit 63 in a well known manner.

The relay unit 63 has a pair of conductors 66 leading to the burner valve, fuel pump or other fuel supply means for the furnace l0, conductors 61 leading to a reverse acting thermostat 64, conductors 68 leading to the motor 32, conductors 69 leading to the motor or solenoid 46, and conductors 10 leading to the fan motor 31.

All of the temperature and humidity control means per se form no part of the present invention, and may be of any well known constructions.

When the temperature in the rooms is sufficiently high the thermostat 60 will close circuits through the relay to shut off the burner through the conductors 66 and stop the fan .36. When the temperature in the interchanger has dropped below a given limit, a thermostat bulb 65 in the cupola 25 acts through a circuit closer 64 and the relay 63 to stop the fans 30.

In the operation of the apparatus, when the temperature of the rooms is below the setting of the thermostat 6|], the furnace I0 and the fan 36 are simultaneously started through the thermostatic control means described. The operation of the fan 36 creates a slight vacuum in the pipe It, so that air is induced through the slots 56 into said pipe. The damper 45 is closed, and the flue gases in passing through the duct 40 open the swinging check valve 44. Any back draft during this operation is prevented as a result of the pressure produced by the fan 36.

The mixture of flue gases and fresh air is introduced into the chamber 23 of the heat exchanger passes at a comparatively low speed through the tubes l8 into the chamber 24, and is forced by the fan 36 through the duct 40 and into the chimney 4|. When the temperature in the heat exchanger I1 is below the setting of the thermostat 64, the fans 30 are started in operation through the thermostat control means described, to draw air through the filtering bed 21, Y and around the tubes l8, thereby causing this air to be heated by the warm mixture of flue gases and air passing through said tubes. The heated fresh air is delivered through the branch ducts 26 into the rooms to supplement the heating of the radiator units I3 and at the same time create slight positive pressure in the heated areas to prevent draft into the room through windows and doors and to provide ventilation. The drawing of comparatively cool air through the heat exchanger H and around the tubes l8 causes the temperature of the mixture of flue gases and air to be lowered, so that when this mixture reaches the chamber 24 the temperature thereof will be below its dew point. The lowering of the temperature of this mixture of flue gases and air, causes a condensation of a substantial portion of its water vapor, and as the particles of condensed water drop they wash and scrub the flue gases and remove the ordinarily objectionable ingredients of said gases, including soot and dust. The

provision of a glass in the door 22 serves not only mixture into the upper end of the heat exchanger I1. However, as soon as the humidity reaches below a predetermined value as determined by the setting of the hygrostat 6|, the operation 'of the motor 46 is initiated torotate the damper 45 into open position, thereby permitting the saturated mixture of flue gases and air to be delivered into the upper end of the heat exchanger. l1 and to be intermixed with the heated fresh air which has been drawn through the filtering bed 21. Enough of this saturated air is introduced into the room through the branch ducts 26 to raise the humidity of the rooms to the setting of the hygrostat 6|. As soon as this condition has been achieved the motor 46 is automatically operated to close the valve.-

When the rooms have reached the temperature setting of the thermostat 60, the furnace "land the draft fan 36 will be shut down. The fans 3|! however will continue to operate until the tem- I perature in the upper end of the heat exchanger I1 is lowered to the setting of the thermostat.

It is seen that by means of the present invention, there is provided an economical process and apparatus, operated entirely automatically for heating and humidifying a room. Also by means of the present construction, any particular area or part of a building such as a solarium, can be heated above the central point determined by the thermostat 60, by a proper setting of the thermostat 6t.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. The process of heating and humidifying a room, which includes the steps of introducing air into the flue gases from a gas furnace, passing the mixture of flue 'gasesand air into heat exchange relationship with a separate body of air to raisegthe temperature of said body of air,

and to lower the'temperature of said mixture sufliciently to cause condensation of a substantial portion of the water vapors in said mixture, whereby said mixture is washed and scrubbed of its objectionable ingredients, and injecting the resultant heated body of air and a small portion of the saturated mixture into said room in controlled relative proportions.

2. A combined heating and air conditioning unit comprising a gas furnace, means for lowering the temperatureof the flue gases from said furnace below their dew point, and means for injecting a small portion of the resultant saturated flue gases into a room to be air conditioned.

3. A combined heating and air conditioning unit for a room comprising a gas furnace, a

radiator in said room, a piping system between said furnace and said radiator for delivering heating fluid to said radiator, a heat exchanger, a flue pipe connection between said furnace and said heat exchanger, means for drawing air into said heat exchanger in heat exchange relationship with the' flue gases delivered thereto, and in suiiicient amounts to lower the temperature of said flue gases below their dew point, and means for injecting a small portion of the resultant saturated flue gases into said room.

4. A combined heating and air conditioning unit comprising a gas furnace, a heat exchanger having a series of substantially parallel tubes, and a pair of chambers disposed on opposite ends of said tubes, and communicating with the interior of said tubes, a flue pipe connection between said furnace and one of said chambers, a passageway between the other chamber and a room to be humidified, means for drawing air into said heat exchanger and around said tubes in suflicient'amounts to lower the temperature of said flue gases belomtheirg dew point, means for delivering a portion of said flue gas to the outside atmosphere and a portion of said passageway, and a humidostat in said room to control the amount of -said last mentioned portion.

5. A combined heating and air conditioning unit comprising a gas furnace, a heat exchanger, a flue pipe connection between said furnace and said exchanger for introducing flue gases into said exchanger, said exchanger having an inlet through which air is drawn therein, a fan in said exchanger for drawing air through said inlet in heat exchange relationship with said flue gases, and in suflicient amounts to lower the temperature of said flue gases below their dew point, a filtering bed across said inlet for filtering the air drawn into said exchanger, and meansfor delivering a part of the saturated flue gases from said heat-exchanger into a room to be humidified.

6. A combined heating and air conditioning unit comprising a gas furnace, a heat exchanger, for lowering the temperature of the flue gases from said furnace below their dew point; a passageway between the outlet of said exchanger and a room to be humidified, for delivering the saturated flue gases intosaid room, a valve in said passageway, and means automaticallyre sponsive to the humidity condition in said room for operating said valve.

7. A combined heating and air conditioning unit for a room, comprising agas furnace, a

sageway having two branch ducts, one leading to a chimney and the other leading to the heated air emerging from said heat exchanger, a pipe connection between said heat exchanger and said room for delivering the mixture of saturated flue gases and heated air into said room, a, valve in said last mentioned duct, and means automatically responsive to the humidity condition in said room for controlling the operation of said valve.

8. A combined heating and air conditioning unit for a. room, comprising a gas furnace, a flue pipe connected with said furnace and having a branch leading to the outside atmosphere and a branch leading to said room, a damper in said last mentioned branch and a humidostat in said room for controlling said damper and thereby controlling the amount of moisture laden flue gas delivered to the room in accordance with the relative humidity of the air in the room.

9. The process of heating and humidifying the air of aroom, which includes burning a gaseous fuel, utilizing the resulting .heat to raise the temperature of the room, introducing the air into the flue gases to heat the air and lower the temperature of the flue gases, cooling the mixture of the flue gases and air below their dew point to condense a portion of the moisture, removing from the gas mixture the condensed moisture and any constituents of the gas mixture dissolved and suspended in the condensed moisture, delivering a portion of the resulting purified moisture-saturated gas mixture into said room,'and controlling the volume of said portion in accordance with the humidity of the air in the room.

10. The process of heating and humidifying the air of a room, which includes burning a gaseous fuel, introducing air into the flue gases to heat the air and lower the temperature of the flue gases, passing the mixture in heat exchange relationship with the current'of air to cool said mixture below the dew point to condense a portion of the moisture and thereby effect washing and scrubbing of the flue gases, removing from the gas in accordance with the humidity of the air in the room.

11. The process of heating and humidifying the air of a room, which includes burning a gaseous fuel, passing the flue gases into heat exchange relationship with a current of air to cool said flue gases below their dew point to condense a portion of the moisture and thereby effect washing and scrubbing of the flue gases, removing from the flue gases the condensed moisture and any constitutent of the gas mixture dissolved and suspended in the condensed moisture, and delivering the said air current and a portion only of the resulting purified moisture-saturated flue gases.

into said room.

12. The process of humidifying a room, which includes the steps of burning a gaseous fuel, lowering the temperature of the flue gases below their dew point to thereby condense moisture from the flue gases and remove constituents of the flue gases, separating the condensate from the purified moisture-saturated flue gases, and delivering a portion of said purified flue gases to the room to humidify the latter.

13. A combined heating and air conditioning unit for aroom comprising a gas furnace, a heat exchanger, a flue pipe connection betweenvsaid furnace and said heat exchanger, means for drawing air through said heat exchanger in heat exchange relationship with the flue gases and in sufilcient amount to lower the temperature of said flue gases below their dew point and thereby condense moisture from said flue gases, said heat exchanger having an outlet for the condensed moisture and any constituents of the flue gases dissolved or suspended therein, means for injecting a small portion of the resulting saturated purified fiue gases into said room, means for delivering the air from said heat exchanger to said room, and means for controlling the amount of the flue gases delivered to said room in accordance with the humidity conditions in said room.

CHARLES H. WAGNER. 

